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Testing spark on a VW MK4 golf 1.4 2000

Good morning my fellow car maintainers :)

Been have a few troubles with sarting the car in suibject. Usually if I drive a short distance, car does not get up to temp turn off, the car refuses to start again. Its got a good working battery, starter motor is doing its job but it just will not fire into life. But if I leave the car after its reached 90 (temp)come back it starts. So I left it an hour or so came back to it and it started fine, first go and fairly fast.

After readind the haynes, and brushing up on the fuel system a bit. My amateur diagnosis is something in the fuel system not functioning or a relay, block fuel filter, fuel pump knackered.

I wanted to try and confirm the engines getting a good spark but am unsure on how to test for this. The engine has 4 seperate coild packs on top of spark plugs. I just was after some advice on this problem and also how to test for a good spark to rule out the crank sensor to help confirm a fuel problem.

Thank you kindly gentlemen.

Reply to
Peter smith
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Not with any kit you've got or are likely to want to buy.

Pull the plugs out and see what colour they are. If they're black and sooty, change them.

If it's running fine once it's started, it's not coil packs.

Reply to
Conor

Hook it up to vagcom and run a scan. This will read the ecu for any error codes.

Reply to
Slider

Engine coolant temp sensor is one of the common issues with the mk4 golf (along with MANY more). If vagcom reports this faulty, I would be inclined to think this is the cause.

Reply to
Slider

I'd agree. The other possibility is flooding maybe?

Reply to
Chris Bartram

Hello :)

All vag com out today lol shows no fault codes. Spark plugs have been re-gapped and look good. Throttle body has been cleaned. Temp sender changed today, no change. Car has been recently serviced so everythings in order.

My vw specialist said it could be the fuel pump relay or fuel pump or a gummed up fuel filter.vSo that lot might be my next port of call, starting with the fuel filter :) being cheap and easy.

Although the haynes says to depresurise the system, so fuel does go shooting everywhere when you pull the lines out. Does say how though ?

Reply to
Peter smith

Interesting I shall add to my fix list :) lol. I've had a million and one common mk4 golf faults, window regulator failure, boot leak, coil packs, door lock module failure, easily fixed with re-soldering the dry joints but time consuming stripping the door down, God knows what else.

In honesty it has been a reliable car, the faults are just niggly and quite expensive fixes. I've fixed them all myself with help and guides from the vw vortex site and ukmkivs site.

Reply to
Peter smith

My wife drives the car a lot so that might be a possibility. How do I go about checking this and if it is how do I clear the flooding ?

Reply to
Peter smith

The usual symptom is a fuel smell. Most cars can be cleared by flooring the throttle while cranking, but I'm not sure if this applies to the VW engine.

You really should get VAG-COM/VCDS or a dealer diag machine on it though.

Reply to
Chris Bartram

Pull the fuel pump relay or fuse, start the car. When it dies, the system is de-pressurised.

Reply to
Chris Bartram

Top man, I had just found the sub section in the haynes refering to easing the pressure.

Reply to
Peter smith

It has been scanned and is showing no faults on VAG COM, sadly.

Reply to
Peter smith

If the plugs were worn enough to need re-gapping then you should really replace them.

Reply to
Mrcheerful

Does the coolant temperature seem realistic though? It reading the wrong value won't give a fault code.

Reply to
Duncan Wood

The car takes about 10 minutes of normal driving and it gets up to 90c in about that and stays on that. Doesn't creep up or down. Seems to be functioning ok.

Reply to
Peter smith

Is that the same temperature sensor on a golf?

Reply to
Duncan Wood

The temp sensor on the golf has two circuits I think. I think one controls the temp gauge on your dash, the other is for ECU to determine fuelling etc (adds extra fuel when cold). Even if the dash temp gauge appears to work correctly, the other circuit could be faulty.

Reply to
Slider

You can read what the ECU thinks the temp is with VAG-COM.

Reply to
Chris Bartram

True. Vagcom is essential for any VAG owner in my opinion.

Reply to
Slider

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